Heavy duty gas turbines may be operated on natural gas, light crude oil, heavy fuel oil, residual fuel oil, and other types of low grade combustible liquid fuels. (The various fuels in single or in combination will be referred to as heavy fuel oil herein.) Such low grade fuels may be relatively inexpensive but such fuels may contain undesirable contaminants such as vanadium and other types of metallics. During combustion, vanadium reacts to form undesirable corrosive compounds such as vanadium oxide (V2O5). These vanadium compounds may have a corrosive effect on hot gas path components in the gas turbine engine. Specifically, vanadium compounds may form hard corrosive deposits on the turbine nozzles and buckets so to reduce hot gas path component lifetime and overall performance and reliability.
Magnesium-based compounds may be added to the flow of fuel so as to mitigate the corrosive effects of vanadium. Magnesium may form relatively low melting alloys with vanadium. These magnesium alloys may be removed more easily from the surface of turbine nozzles, buckets, and other hot gas path components. Known methods for adding magnesium to the flow of fuel oil, however, may result in a non-homogenous mixture of the protective magnesium in the fuel stream. As such, not all of the hot gas path components may be adequately or consistently protected. Moreover, magnesium slugging in the flow of fuel oil may disrupt the operation of the entire fuel delivery system.
There is thus a desire for improved systems and methods for providing heavy fuel oils and the like with treatment for impurity removal for combustion in a gas turbine engine. Such improved systems and methods may better deliver magnesium to the flow of heavy fuel oil so as to reduce hot gas path component corrosion and, hence, improve component lifetime with increased overall gas turbine performance and reliability.